Day34.爬虫基础之Selenium

关注

原创最新推荐文章于 2026-02-28 15:56:07 发布 322 阅读 AI 写同款· GEO 优化 ›

uniapp - Invalid value “iife” for option “output.format” - UMD and IIFE output formats are not suppo Invalid value “iife” for option “output.format” - UMD and IIFE output formats are not supported for code-splitting builds. uniapp 编译报错，vite vue3 Hbuilder 中编译报错，uniapp 打包 App 报错（vue3）hbuilder提示错误，uniapp运行到手机/模拟器 App 报错（vue3）uniapp项目启动报错，如何解决这个问题，安卓app，苹果app 阅读详情

爬虫基础之Selenium

前言

本文主要是展示了Selecium库的基础知识和简单操作。

一. Selenium 基本操作

1.1 简单使用

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.support.wait import WebDriverWait

browser = webdriver.Chrome()  # 新建一个浏览器窗口
try:
    browser.get('https://www.baidu.com')  # 访问特定URL
    input_info = browser.find_element_by_id('kw')  # 找到为 kw 的 id
    input_info.send_keys('Python')  # 输入为 Python 的关键词
    input_info.send_keys(Keys.ENTER)  # 点击 ENTER 直接进入
    wait = WebDriverWait(browser, 10)  # 设定最大的等待响应时间
    
    # 等待指定的元素出现。
    wait.until(EC.presence_of_element_located((By.ID, 'content_left')))
    print(browser.current_url)
    print(browser.get_cookies())
    print(browser.page_source)
    
finally:
    browser.close()  # 最后，关闭浏览器。

1.2 声明浏览器对象

from selenium import webdriver

browser = webdriver.Chrome()  # 指定特定的浏览器操作。
browser = webdriver.Firefox()
browser = webdriver.Edge()
browser = webdriver.PhantomJS()
browser = webdriver.Safari()

1.3 访问页面

from selenium import webdriver

brower = webdriver.Chrome()
brower.get('heeps://www.taobao.com')
print(brower.page_source)
brower.close()

1.4 查找元素

1.4.1 单个元素

from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.taobao.com')

# 使用不同的方式进行查找同一个内容 id css_selector xpath
input_first = browser.find_element_by_id('q')
input_second = browser.find_element_by_css_selector('#q')
input_third = browser.find_element_by_xpath('//*[@id="q"]')

print(input_first, input_second, input_third)
browser.close()

1.4.2 一些查找元素的其他方法

find_element_by_name
find_element_by_xpath
find_element_by_link_text
find_element_by_partial_link_text
find_element_by_tag_name
find_element_by_class_name
find_element_by_css_selector

from selenium import webdriver
from selenium.webdriver.common.by import By

browser = webdriver.Chrome()
browser.get('heeps://www.taobao.com')
input_first = browser.find_element(By.ID, 'q')
print(input_first)
browser.close()

1.4.3 多个元素

from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
lis = browser.find_elements_by_css_selector('.service-bd li')
print(lis)
browser.close()

# 类似于上面的这种方法
browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
lis = browser.find_elements(By.CSS_SELECTOR, '.service-bd li')
print(lis)
browser.close()

二. Selenium 高级操作

2.1 元素交互操作

对获取的元素调用交互方法

from selenium import webdriver
import time

browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
inpit_info = browser.find_element_by_id('q')
input_info.send_keys('iphone')
time.slees(1)
input_info.clear()
input_info.send_keys('iPad')
button = browser.find_element_by_class_name('btn-search')
button.click()

更多操作: http://selenium-python.readthedocs.io/api.html#module-selenium.webdriver.remote.webelement

2.2 交互动作

将动作附加到动作链中串行执行

from selenium import webdriver
from selenium.webdriver import ActionChains

browser = webdriver.Chrome()
url = 'http://www.runoob.com/try/try.php?filename=jqueryui-api-droppable'
browser.get(url)
browser.switch_to.frame('iframeResult')  # 传入frame参数
source = browser.find_element_by_css_selector('#draggable')
target = browser.find_element_by_css_selector('#droppable')
actions = ActionChains(browser)  
actions.drag_and_drop(source, target)  # 拖拽操作
actions.perform()  # 执行拖拽

更多操作: http://selenium-python.readthedocs.io/api.html#module-selenium.webdriver.common.action_chains

2.3 执行 JavaScript

from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.zhihu.com/explore')

# 进度条的拖拽
browser.execute_script('window.scrollTo(0, document.body.scrollHeight)')
browser.execute_script('alert("To Bottom")')  # 拖拽到底部。

2.4 获取元素信息

2.4.1 获取属性

from selenium import webdriver
from selenium.webdriver import ActionChains

browser = webdriver.Chrome()
url = 'https://www.zhihu.com/explore'
browser.get(url)
logo = browser.find_element_by_id('zh-top-link-logo')
print(logo)
print(logo.get_attribute('class'))

2.4.2 获得文本值

from selenium import webdriver

browser = webdriver.Chrome()
url = 'https://www.zhihu.com/explore'
browser.get(url)
input_info = browser.find_element_by_class_name('Sticky AppHeader')
print(input_info.text)

2.4.3 获取ID，位置，标签名，大小

from selenium import webdriver

browser = webdriver.Chrome()
url = 'https://www.zhihu.com/explore'
browser.get(url)
input_info = browser.find_element_by_class_name('zu-top-add-question')
print(input_info.id)
print(input_info.location)
print(input_info.tag_name)
print(input_info.size)

2.4.4 Frame

import time
from selenium import webdriver
from selenium.common.exceptions import NoSuchElementException

browser = webdriver.Chrome()
url = 'http://www.runoob.com/try/try.php?filename=jqueryui-api-droppable'
browser.get(url)
browser.switch_to.frame('iframeResult')
source = browser.find_element_by_css_selector('#draggable')
print(source)
try:
    logo = browser.find_element_by_class_name('logo')
except NoSuchElementException:
    print('NO LOGO')
browser.switch_to.parent_frame()
logo = browser.find_element_by_class_name('logo')
print(logo)
print(logo.text)

2.5 等待

2.5.1 隐式等待

当使用了隐式等待执行测试点时候，如果 WebDriver 没有在 DOM 中找到元素，将继续等待，超出设定时间后则跑出找不到元素的异常。换句话说，当查找元素或者元素并没有立即出现的时候，饮食等待将等待一段时间再查找 DOM，默认时间为0.

from selenium import webdriver

browser = webdriver.Chrome()
browser.implicitly_wait(10)
browser.get('https://www.zhihu.com/explore')
input = browser.find_element_by_class_name('zu-top-add-question')
print(input)

2.5.2 显式等待

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

browser = webdriver.Chrome()
browser.get('https://www.taobao.com/')
wait = WebDriverWait(browser, 10)
input_info = wait.until(EC.presence_of_element_located((By.ID, 'q')))
button = wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR, '.btn-search')))
print(input_info, button)

title_is 标题是某内容
title_contains 标题包含某内容
presence_of_element_located 元素加载出，传入定位元组，如(By.ID, ‘p’)
visibility_of_element_located 元素可见，传入定位元组
visibility_of 可见，传入元素对象
presence_of_all_elements_located 所有元素加载出
text_to_be_present_in_element 某个元素文本包含某文字
text_to_be_present_in_element_value 某个元素值包含某文字
frame_to_be_available_and_switch_to_it frame加载并切换
invisibility_of_element_located 元素不可见
element_to_be_clickable 元素可点击
staleness_of 判断一个元素是否仍在DOM，可判断页面是否已经刷新
element_to_be_selected 元素可选择，传元素对象
element_located_to_be_selected 元素可选择，传入定位元组
element_selection_state_to_be 传入元素对象以及状态，相等返回True，否则返回False
element_located_selection_state_to_be 传入定位元组以及状态，相等返回True，否则返回False
alert_is_present 是否出现Alert

详细内容：http://selenium-python.readthedocs.io/api.html#module-selenium.webdriver.support.expected_conditions

2.6 前进后退

import time 
from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.baidu.com/')
browser.get('https://www.taobao.com/')
browser.get('https://www.python.org/')
browser.back()
time.sleep(2)
browser.forward()
browser.close()

2.7 Cookies

from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.zhihu.com/explore')
print(browser.get_cookies())
browser.add_cookie({'name':'name', 'domain':'www.zhihu.com','value':'germey'})
print(browser.get_cookies())
browser.delete_all_cookies()
print(browser.get_cookies())
browser.close()

2.8 选项卡管理

import time
from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.baidu.com')
browser.execute_script('window.open()')  # 在同一个浏览器界面上打开一个新的选项卡
print(browser.window_handles)
browser.switch_to_window(browser.window_handles[1])
browser.get('https://www.taobao.com')
time.sleep(1)
browser.switch_to_window(browser.window_handles[0])
browser.get('https://python.org')
time.sleep(3)
browser.close()

2.9 异常处理

from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.baidu.com')
browser.find_element_by_id('hello')  # id 不存在

# +++++++++++++++++++++++++++++++++++++++++++++++++ #
from selenium import webdriver
from selenium.common.exceptions import TimeoutException, NoSuchElementException

browser = webdriver.Chrome()
try:
    browser.get('https://www.baidu.com')
except TimeoutException:
    print('Time Out!')
    
try:
    browser.find_element_by_id('hello')
except NoSuchElementException:
    print('No Element')
finally:
    browser.close()